Blends of polypropylene (PP) and low-density polyethylene (LDPE) with and without ethylene-propylene-diene (EPDM) terpolymer as a compatibilizer were studied. Mechanical properties were chosen to estimate the compatibilization efficiency of EPDM. The interactions between phases were valued through glass transition shifts in dynamic mechanical spectra, and morphology of the blends was obtained using scanning electron microscopy. Interfacial adhesion was improved by EPDM addition. Addition of EPDM to PP/LDPE blends improved mechanical properties, especially Izod impact strength in LDPE-rich blends and with higher EPDM content.

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This article presents an investigation about the polymer-modified bitumens (PMBs) containing styrene-butadiene-styrene (SBS) block copolymers with different structures, linear (SBS-L) and radial (SBS-R), semicrystalline copolymer ethylene-vinyl acetate (EVA), and terpolymer ethylene-butyl acrylate-glycidyl methacrylate, Elvaloy AM and Elvaloy 4170. The aim of the study was to establish the influence of the polymer type and content on the properties of PMBs for engineering applications and to evaluate the effectiveness of polymer modifiers. The results indicated that the polymer modification improved the rheological properties of bitumen, increased critical temperature, that is better resistance to permanent deformation was achieved as well as a wider temperature range in service. The degree of improvement generally increased with the polymer content but varied with the polymer type.

Blends of isotactic polypropylene (iPP) and high density polyethylene (HDPE) with and without ethylene-propylene-diene (EPDM) terpolymer as compatibilizer were systematically investigated to determine the influence of the EPDM on blends properties. The morphology was studied by Scanning Electron Microscopy (SEM). Mechanical properties of investigated systems: tensile strength at break, elongation at break, yield stress and Izod impact strength were determined. Crystallization behavior was determined by Differential Scanning Calorimetry (DSC). Dynamic Mechanical Analysis (DMA) was used to determined the storage modulus (E 0 ), loss modulus (E 00 ), and loss tangent (tan d). The PPþHDPE blend revealed poor adhesion between PP and HDPE phases. Finer morphology was obtained by EPDM addition in PPþHDPE blends and better interfacial adhesion. Addition of HDPE to PP decreased tensile strength at break, elongation and yield stress. Decrease of tensile strength and yield stress is faster with EPDM addition in PPþHDPE blends. Elongation at break and impact strength was significantly increased with EPDM addition. The addition of EPDM in PPþHDPE blends did not significantly change melting points of PP phase, while melting points of HDPE phase was slightly decreased in PPþHDPEþEPDM blends. The EPDM addition increased the percentage of crystallization (X c ) of PP in PPþHDPE blends. The increase of X c of HDPE was found in the blend with HDPE as matrix. Dynamical mechanical analysis showed glass transitions of PP and HDPE phase, as well as the relaxation transitions of their crystalline phase. By addition of EPDM glass transitions (T g ) of HDPE and PP phases in PPþHDPE blends decreased. Storage modulus (E 0 ) vs. temperatures (T) curves are in the region between E 0 /T curves of neat PP and HDPE. The decrease of E 0 values at 25 8C with EPDM addition in PPþHDPE blends is more pronounced.

The objective of this study is to examine the influence of poly [styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) compatibilizer on the morphology and properties of atactic polystyrene/high density polyethylene (aPS/HDPE) blends. The rheological behavior of the blends melt during processing is followed. The concentration of SEBS does not significantly influence the processing parameters. The morphology is determined by SEM and TEM. aPS/HDPE/SEBS blends exhibit fine dispersion of HDPE or aPS particles in the matrix and better adhesion at the interface. Higher concentration of SEBS results in better compatibility. Transmission electron micrographs confirm existence of the SEBS interfacial layer between the aPS and the HDPE phase. This effect is stronger in the blends with higher SEBS concentration and HDPE as matrix. The mechanical properties are determined. The tensile strength decreases while the elongation at break and the impact strength increase with the SEBS content. The results prove that SEBS acts Downloaded from as a compatibilizer in aPS/HDPE blends and its effect is more expressed in blends with a higher SEBS content and HDPE as matrix.